Hi, Welcome to sevenforums.
Can you post your complete system configuration? Like your motherboard etc.
We would like to know what kind of slot your mobo has. AGP or PCIe.
If AGP, then I will suggest Radeon HD 3450 Video Card - 512MB, DDR2, AGP 8X, DVI, VGA, DirectX 10.1, Single-Slot. Price 69.99$
If PCIe, go to this link and check it out. Newegg.com - Computer Hardware, Video Cards & Video Devices, Desktop Graphics Cards, PCI Express x1, DirectX 11